This project is part of the continuing studies, using protein semisynthesis to understand the relationship between primary structure of proteins and the higher order properties of folding, interactions, and ultimate biological functions. Sequence modeling studies of ribonuclease have been undertaken, which involve the design and the chemical semisynthesis of model proteins with specific chemical and conformational properties directed artificially. The studies of semisynthetic model proteins have provided the insight into the mode of noncovalent interaction between RNase-(1-20) and RNase-(21-124). The studies of neurophysins and their precursors is also progressing through tbeir semisynthesis in order to investigate hormone-protein interaction, folding of proteins, and biosynthetic pathway of hormones.